Cardiac rhythm management devices are implantable devices that provide electrical stimulation to selected chambers of the heart in order to treat disorders of cardiac rhythm. A pacemaker, for example, is a cardiac rhythm management device that paces the heart with timed pacing pulses. The most common condition for which pacemakers have been used is in the treatment of bradycardia, where the ventricular rate is too slow. If functioning properly, the pacemaker makes up for the heart's inability to pace itself at an appropriate rhythm in order to meet metabolic demand by enforcing a minimum heart rate and/or artificially restoring AV conduction. Implantable devices may also be configured to treat tachyarrhythmias such as fibrillation with electrical stimulation.
As a part of performing their functions in delivering therapy, implantable cardiac devices may equipped with various sensing modalities for detecting cardiac electrical activity as well as measuring other physiological parameters. Other types of implantable devices may be configured for delivering other types of therapy and/or only monitoring particular physiological parameters. A patient management system may be constructed of an implantable device configured with a telemetry system for communicating such collected data to an external device and ultimately to clinical personnel for evaluation.